The invention relates to the field of semiconductor devices and circuits, and particularly to a high-density, 3-dimensional microelectronic capacitor array, methods of manufacturing the same, and methods of operating the same.
Capacitors have found a wide range of applications in integrated semiconductor circuits. For example, high-density capacitors are employed to decouple and stabilize signal and power lines. As the number of integrated circuit components continuously increases from generation to generation, less chip area remains available for building passive devices such as capacitors.
Without a decoupling capacitor that provides sufficient capacitance, coupling noise can jeopardize signal integrity in high-speed circuits. Further, a large capacitor is needed for many circuits application including, for example, PLL (phase lock loop) circuits, charge pump circuits, analog circuits, and ESD (electro-static discharge) protection circuits.
To increase capacitance of a capacitor without a corresponding increase in circuit area used for the capacitor, some of the advanced semiconductor chips employ a thin node dielectric material for the capacitor. As the thickness of the node dielectric decreases, leakage current through the capacitor increases. The increase in the leakage current becomes a serious problem for a high-density capacitor because a leaky capacitor is electrically equivalent to a resistor in an unwanted place that reduces the supply voltage and increases power consumption of the circuit. Further, a leaky capacitor is known to cause a problem for many circuits. For example, a leaky capacitor is a major contributor to jitter noise in a PLL circuit.